What are open loop payments?
Open loop payments are transactions that process across a shared network, allowing any enrolled bank, merchant, or financial institution to participate regardless of which specific provider issued the payment method. The sender and recipient do not need to be customers of the same institution. The network acts as the common infrastructure connecting them.
Visa and Mastercard are the most widely recognized open loop systems. A Visa card issued by one bank can be used at any merchant that accepts Visa, regardless of which bank the merchant uses. The same logic applies to payment rails: ACH, RTP, and FedNow are open loop because any enrolled financial institution can send and receive payments through them, not just customers of a single provider.
How open loop payments work
An open loop payment involves multiple parties, each playing a distinct role in the transaction:
- Issuing bank: The financial institution that issued the customer's card or payment credential. It manages the customer's account, approves or declines the transaction, and bears the credit or fraud risk
- Card network or payment rail: The shared infrastructure that routes the transaction between the issuer and the acquirer. For cards: Visa, Mastercard, or Amex. For bank transfers: ACH, RTP, FedNow, SWIFT
- Acquiring bank: The financial institution that processes payments on behalf of the merchant. It receives the transaction from the network and credits the merchant's account
- Merchant: Accepts the payment through a terminal, payment gateway, or API connection to their acquirer
Each party earns a portion of the transaction. Interchange fees flow from the merchant's acquirer to the issuing bank, with the card network taking a separate scheme fee. This multi-party structure is what makes open loop systems more expensive per transaction than closed loop alternatives.
Examples of open loop payment systems
Open loop systems are everywhere, spanning both card networks and bank-to-bank payment rails:
- Visa and Mastercard: Credit and debit cards accepted at tens of millions of merchants globally
- American Express: Operates as both network and issuer in many markets
- ACH: The US bank-to-bank transfer network connecting thousands of financial institutions for direct deposits, bill payments, and business transfers
- RTP and FedNow: US instant payment rails open to any enrolled bank or credit union
- SEPA: The European open loop bank transfer system connecting thousands of banks across the eurozone
- Zelle: Connects enrolled US banks for instant person-to-person transfers without requiring both parties to use the same app
Open loop vs. closed loop payments
Each model makes a different set of tradeoffs. Understanding the difference is important for anyone choosing which payment infrastructure to build on.
Closed loop systems trade acceptance breadth for lower cost, better data, and tighter control. Open loop systems trade those advantages for universal reach. The right choice depends on the use case. See the closed loop payments entry for a full breakdown of the closed loop model.
Why open loop matters for payment platforms
For fintechs, neobanks, and payment service providers building payment products, the open loop model is typically the default. Connecting to open loop rails via a payment API gives immediate access to the existing banking infrastructure, without needing to build a proprietary network or convince both parties to join the same system.
The tradeoff is cost and data. Open loop rails carry interchange and scheme fees that compound at high volumes. And because transactions cross multiple institution boundaries, the originator typically sees less customer spend data than a closed loop operator would. Platforms that want to combine open loop reach with closed loop economics and data often build hybrid structures: accepting open loop payment methods at the front end while moving funds through internal ledgers or virtual accounts before settling externally.
